"PRODUCT SAFETY WARNING AND REPLACEMENT NOTICE. Attention owners of Winchester model 100 rifles and carbines please read this notice. In July of 1990 the following product safety warning was issued by Winchester. It has come to our attention that the firing pin in the Winchester Model 100 Rifle or Carbine may break due to use and metal fatigue and become lodged in the breech bolt face. If this occurs, the firearm may fire before the action is locked causing severe damage to the firearm and possibly injury or death to the shooter and bystander.

WARNING DO NOT SHOOT YOUR WINCHESTER MODEL 100 RIFLE OR CARBINE. Repair and replacement. A new firing pin has been designed to replace the firing pin originally made for the Winchester Model 100 Rifle and Carbine. The new firing pins will be available in April 1991. If you own a Winchester Model 100 Rifle or Carbine, please send your firearm to one of the authorized Winchester Model 100 Firing Pin Replacement Centers indicated below. Your Winchester Model 100 firearm will be inspected, the firing pin replaced and tested and the firearm returned to you. The inspection, replacement/testing and return postage will be accomplished at no cost to you. If other repair or maintenance work is authorized by you to be performed on the firearm when the firing pin is replaced, such work shall be at your cost."

-------------------------The difference in the old firing pin and the new one is as follows. The old replaced style, was totally lathe tuned (round). While the new recall style is similar in lathe turning on the front and back, but in the front midsection it has two flats milled, one on each side. This makes the center section stronger. Also replaced is the bolt sleeve lock pin (firing pin guide) which was made to accommodate this different shaped firing pin

Part number for the new parts are, firing pin =1391ND, bolt sleeve locking pin =1491ND

The word was at the time this recall was in process was that if the firing pin would break at the mid section and still remain in the gun as two pieces, the possibility of a premature discharge before the bolt was locked was possible. This apparently was caused by the firing pin tip (now not having a retracting spring) to be stuck forward, and thereby slam-firing upon chambering.

The responsibility for the recall apparently was on Olin, as they were the parent company at time of manufacture. Olin set up regional recall centers at three established US gunshops. There was a manufacturing delay in the replacement firing pins, and a backlog occurred, also some collectors did not like the idea of shipping their guns long distances. Olin then also authorized other gunshops to make the required alterations. Upon completion of the recall, the shops were to test fire the firearm and to stamp an assigned letter on the inside top of the receiver as seen thru the magazine well with the bolt retracted. The letter "B" represented Bolsa Gunsmithing, "L" was Lefever, and "N" was for Nu-line Guns. The letter "X" apparently was for all the other independent shops. However this identification information did not get communicated to some of the smaller shops at the start of the project. The only way to tell if the gun as been modified, if the "letter" is not present, is to take the barrel & action out of the stock, remove the trigger guard assembly and the try to rotate the firing pin by twisting it. If it does NOT rotate, then the firing pin recall HAS been performed.